Genetic types and distinguished characteristics of dolomite and the origin of dolomite reservoirs

Wenzhi ZHAO,Anjiang SHEN,Zhanfeng QIAO,Liyin PAN,Anping HU,Jie ZHANG

Table 1 Classification of dolomite corresponding to the classification of limestone established by Dunham[36, 38].

Limestone classification established by Dunham Identifiable primary texture Crystal grain texture with unidentifiable sedimentary structures (grain size/mm) Original structural components have not been bonded together during deposition Original structural components are bonded during deposition Lime mud-bearing (clay or silt-sized carbonate rock) Lime mud-lacking, grain-supported Lime mud-supported Grain- supported Grain content < 10% Grain content > 10% Micrite limestone Wackestone Packstone Grain dolomite Bondstone Crystalline limestone Classification of dolomite corresponding to that proposed by Dunham Micritic dolomite Wackestone Packstone Grain dolomite Reef dolomite Algal mound dolomite Very finely crystal dolomite (0.03-0.10) Fine crystalline dolomite (0.10-0.25) Medium crystalline dolomite (0.25-0.50) Coarse crystalline dolomite (0.50-2.00) Macro crystalline dolomite ( > 2.00)